assoc.h

/*
 * arcus-memcached - Arcus memory cache server
 * Copyright 2010-2014 NAVER Corp.
 * Copyright 2015 JaM2in Co., Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#ifndef ASSOC_H
#define ASSOC_H

typedef struct _prefix_t prefix_t;

struct _prefix_t {
    uint8_t nprefix;

    uint32_t prefix_items;
    uint64_t list_hash_items;
    uint64_t set_hash_items;
    uint64_t btree_hash_items;
    uint64_t hash_items;
    //uint64_t tot_hash_items;

    prefix_t *h_next;

    rel_time_t oldest_live;
    time_t create_time;

    uint64_t list_hash_items_bytes;
    uint64_t set_hash_items_bytes;
    uint64_t btree_hash_items_bytes;
    uint64_t hash_items_bytes;
    //uint64_t tot_hash_items_bytes;

    prefix_t *parent_prefix;
};

struct bucket_info {
    uint16_t refcount; /* reference count */
    uint16_t curpower; /* current hash power:
                        * how may hash tables each hash bucket use ? (power of 2)
                        */
};

struct assoc {
   uint32_t hashpower; /* how many hash buckets in a hash table ? (power of 2) */
   uint32_t hashsize;  /* hash table size */
   uint32_t hashmask;  /* hash bucket mask */
   uint32_t rootpower; /* how many hash tables we use ? (power of 2) */

   /* cache item hash table : an array of hash tables */
   struct table {
      hash_item** hashtable;
   } *roottable;

   /* bucket info table */
  struct bucket_info *infotable;

   /* prefix hash table : single hash table */
   prefix_t**  prefix_hashtable;
   prefix_t    noprefix_stats;

   /* Number of items in the hash table. */
   unsigned int hash_items;
   unsigned int tot_prefix_items;
};

#ifdef JHPARK_KEY_DUMP
#define MAX_SCAN_ITEMS 256
struct assoc_scan {
  int        guard_data;
  int        cur_bucket;
  int        cur_tabidx;
  int        max_bucket;
  int        array_size;
  int        item_count;
  hash_item *item_array[MAX_SCAN_ITEMS];
};
#endif

/* associative array */
ENGINE_ERROR_CODE assoc_init(struct default_engine *engine);
void              assoc_final(struct default_engine *engine);

hash_item *       assoc_find(struct default_engine *engine, uint32_t hash,
                             const char *key, const size_t nkey);
int               assoc_insert(struct default_engine *engine, uint32_t hash, hash_item *item);
void              assoc_delete(struct default_engine *engine, uint32_t hash,
                               const char *key, const size_t nkey);
#ifdef JHPARK_KEY_DUMP
/* assoc scan functions */
void              assoc_scan_init(struct default_engine *engine, struct assoc_scan *scan);
void              assoc_scan_next(struct default_engine *engine, struct assoc_scan *scan);
void              assoc_scan_final(struct default_engine *engine, struct assoc_scan *scan);
#endif
prefix_t *        assoc_prefix_find(struct default_engine *engine, uint32_t hash,
                                    const char *prefix, const size_t nprefix);
bool              assoc_prefix_isvalid(struct default_engine *engine, hash_item *it);
void              assoc_prefix_update_size(prefix_t *pt, ENGINE_ITEM_TYPE item_type,
                                    const size_t item_size, const bool increment);
ENGINE_ERROR_CODE assoc_prefix_link(struct default_engine *engine,
                                    hash_item *it, const size_t item_size,
                                    prefix_t **pfx_item);
void              assoc_prefix_unlink(struct default_engine *engine, hash_item *it,
                                    const size_t item_size, bool drop_if_empty);
ENGINE_ERROR_CODE assoc_get_prefix_stats(struct default_engine *engine,
                                    const char *prefix, const int nprefix,
                                    void *prefix_data);
#endif